IP SLA : set ip next hope

[medharrak]

Hi,

I'm configuring IP SLA in Cisco Router to ping 8.8.8.8 , any idea how to specify the ip next hope?

Thank you

[balaji.bandi]

I am may interpreting wrong here ? what are you looking for next hop syntax ?

example :

http://www.firewall.cx/cisco-technical-knowledgebase/cisco-routers/861-cisco-router-pbr-ipsla-auto-redirect.html

[medharrak]

I'm looking to know if there is a way to specify which output interface to take.

I see in your example that route-map is used

[balaji.bandi]

Sure if you have different path to go out, yes you need to choose which path to choose to reach destination and based on the results take action.

[medharrak]

but my question if how to do it , there is No "ip next hop" command in ip sla .

so what I did is : I added a route to 8.8.8.8/32 to go through a specific interface

[pman]

Your next hop is determined by the routing table.

For example if to get to 8.8.8.8 you exit through Gi0/0/0 at IP address 192.168.1.1/24 (this ip configured on Gi0/0/0):

R1#show ip route 8.8.8.8
Routing entry for 8.8.8.8/32
Last update from 192.168.1.2 on GigabitEthernet0/0/0, 00:17:00 ago

If you work with static routing you can specify the route and the alternate interface through which the next hop should be found:
ip route 0.0.0.0 0.0.0.0 Gi0/0/0

https://www.cisco.com/c/en/us/support/docs/dial-access/floating-static-route/118263-technote-nexthop-00.html#anc5

[paul driver · Accepted solution]

Hello
if i understand you wish to make sure ip sla icmp probe to 8.8.8.8 is only reachable via a certain default path possibly the active default path and negate the probe reaching 8,8,8.8 via an alternate path if/when the current default path becomes unavailable?

example1:
ip sla 1
icmp-echo 8.8.8.8 source-interface fa0/1
timeout 1000
threshold 2000
frequency 15

ip sla schedule 1 start now life forever
track 10 rtr1 reachabilty 

ip route 0.0.0.0 0.0.0.0 fa0/1 x.x.x.x track10  name primary link
ip route 0.0.0.0 0.0.0.0 fa0/0 x.x.x.x 2  name backup link
ip route 8.8.8.8 255.255.255.255 Null0 2

example2:
same ip sla as in example 1
access-list 100  permit icmp host <source ip> host 8.8.8.8 echo
route-map ipsla 
match ip address 100
set ip next-hop (next hop of interface fa0/1)
set interface Null0

ip local policy route-map ipsla 
ip route 0.0.0.0 0.0.0.0 fa0/1 <nexthop ip> track 10 name primary link
ip route 0.0.0.0 0.0.0.0 fa0/0 <nexthop ip> 2 name backup link